Respiration Flashcards
How many molecules of ATP are synthesised during respiration
38
What are the four stages of respiration
Glycolysis
Link Reaction
Krebs Cycle
Electron Transport Chain
Where in the cell does each stage of respiration occur
Glycolysis - cytoplasm
Link Reaction - Mitochondrial Matrix
Krebs Cycle - Mitochondrial Matrix
Electron Transport Chain - Mitochondrial membrane
How many ATPs does NAD make
3
How many ATPs does FAD make
2
What is substrate phosphorylation
ATP generated directly
What is oxidative phosphorylation
ATP generated indirectly using co-enzymes
What are the two stages of glycolysis
Phosphorylation
Oxidation
What occurs during phosphorylation in glycolysis
Glucose -> triose phosphate
Process requires 2 ATP
What occurs during the oxidation stage of glycolysis
Triose phosphate -> pyruvate
4 ATP created
4 H+ released creates 2 red.NAD
What are the products of glycolysis
2x red.Nad, 2x pyruvate, 2x ATP (net)
What occurs in the link reaction
Pyruvate -> Acetyl Co-enzyme A
The 2x pyruvate is decarboxylated to release CO2. It is also dehydrogenated and forms 2x red.NAD. 2x co-enzyme A joins and forms acetyl co-enzyme A.
What are the products of the link reaction
2x acetyl co-enzyme A, 2x red.NAD, 2x CO2
What happens in the Krebs Cycle
A 4-carbon compound combines with acetyl co-enzyme A. This releases co-enzyme A to be used again in the link reaction. The new 6-carbon compound is dehydrogenated and decarboxylated to form a 5-carbon compound, CO2, and red.NAD. This 5-carbon compound is then further decarboxylated and dehydrogenated to create the original 4-carbon compound, CO2, 2x red.NAD, 1x red.FAD, and 1x ATP that is formed directly from substrate phosphorylation.
What are the products of the Krebs Cycle
6x red.NAD, 2xred.FAD, 2xATP, and 4x CO2
How much ATP is made at each stage of respiration
Glycolysis: 2 direct, 6 indirect
Link: 6 indirect
Krebs: 22 indirect, 2 direct
What is the electron transport chain
A series of pumps in the cristae of the mitochondria where redox reactions take place to form ATP. The final electron acceptor in the chain in aerobic respiration is oxygen which makes a safe and stable waste product, water.
What halts in anaerobic respiration
The Krebs cycle and Electron transport chain as without oxygen as the final acceptor it won’t continue. Glycolysis still continues.
What type of anaerobic respiration do animals use
Lactic fermentation
What type of anaerobic respiration do fungi and plants use
Alcoholic fermentation
What happens in lactic fermentation
Glycolysis -> pyruvate + 2H+ -> lactate (+2x ATP)
What happens in alcoholic fermentation
Glycolysis -> pyruvate - CO2 -> ethanal + 2H+ -> ethanol + CO2 (+2x ATP)
How many ATP does anaerobic respiration create
2
How are lipids used in respiration
Lipids are hydrolysed into glycerol + 3x fatty acids
The glycerol is phosphorylated using ATP
It is then dehydrogenated and the NAD is reduced
This forms triose phosphate
The fatty acids are split into 2-carbon molecules and combined with co-enzyme A and enter the Krebs cycle
How are proteins used in respiration
Proteins are hydrolysed into amino acids
These are then deaminated in the liver which removes the NH2 which is turned into urea and excreted by the kidneys
The remainder is converted into either pyruvate or a compound in the Krebs Cycle depending on the amino acids present.
How do you calculate a respiratory quotient
number of molecules of CO2 produced/number of molecules of O2 consumed
